Two men were thwarted in their attempt to rob a bank yesterday when a teller rejected their holdup note -- because it was written on the deposit slip of a different bank.

Police said the teller did not even notice the robbery note when she told one of the men that he could not use a Maryland National transaction slip at the Harbor Bank of Maryland.

So the man with the note and his accomplice watching the door fled the bank office in the first block of W. Fayette St. without getting a dime or putting up a fuss.

The only way anyone knew of the bumbling holdup attempt at 10 a.m. was from a witness -- a woman who had been standing in line behind one would-be robber and read the note over his shoulder.

"He was holding it up as if he was studying it," said the witness, 29, a construction company bookkeeper. "It said, 'I have a gun. Gimme me your money or else.' "

"I was scared," said the witness, a regular customer who is acquainted with the bank staff and was making a company payroll transaction at the time. "But I didn't want to panic and have someone get hurt."

The woman tried unsuccessfully to alert bank employees with hand signals and "lip-syncing," but the note was passed over the counter to the teller.

The teller's response, according to the witness, was: "This is a Maryland National transaction -- you have to go to Maryland National."

As the bandits fled with the note but not any money, the witness finally had her chance to explain what had almost happened.

The city police, summoned by the bank's alarm, broadcast a warning to officers on the street to pay special attention to Maryland National branches in the downtown area -- just in case the bandits followed the teller's directions.

But the duo failed to attempt another criminal withdrawal yesterday -- missing a chance at a record. The 96 bank robberies committed in 1993 match the record for the most in a year, set in 1980.

But the biggest loser was the witness.

She was in the bank for nearly two hours giving statements to investigators and got a parking ticket for her trouble.

"The FBI agent ran outside and told [the parking control officer] I was a bank robbery witness," she said, adding that it was too late -- the ticket had been written.